Dr. Hurtado's answer:(1) How great a role, in orthodoxy’s success, was its claim to apostolic authority?(2) Does orthodoxy’s claim have validity, denied to competitors?
Lots of people and and groups in early Christianity claimed apostolic authority. E.g., many/most of the texts of “heretical” views claim apostolic figures (e.g., Gospel of Thomas, Gospel of Philip, etc.). One difference between the emergent “proto-orthodox” folk and their rivals was that they seem to have gone more for a collective apostolic claim. E.g., the interesting text, “The Epistle of the Apostles” (Epistula Apostolorum) purports to relate how the entire 12 were commissioned by Jesus, and it’s widely recognized that this text was likely written to counter the claims of other Christians about the special authority of this or that individual apostle. LIkewise, the collection that became the NT reflects a clear effort toward an inclusiveness of a certain diversity of apostles and emphases. In its earliest expressions, “proto-orthodox” Christianity = not a single point of view or group but a constellation that was united in their readiness to recognize a certain critical diversity. After all, the early Christian sense of the Greek word for “heresy” (“hairesis”) was a “sect” or “party”.I found this to be a fascinating perspective. The usual, popular-level understanding is that the forces of orthodoxy in the early church were somehow tyrannical in imposing a narrow vision and version of belief. This perspective comes to goofy expression in Dan Brown's The Da Vince Code. Hurtado's brief comment puts this view on the defensive. The NT canonical process did exclude books but it also "reflects a clear effort toward an inclusiveness of a certain diversity of apostles and emphases." This explains the diversity within the NT canon (why we have four gospels, why both Paul and James are kept together, etc.). Who knew orthodoxy could be so tolerant of "inclusivity" and "diversity!"